Although severe lower extremity peripheral arterial disease affects more than 12 million people in the United States,1,2 secular trends in the risk of amputation remain unexplored in recent years. Using national billing and survey data sets from the Centers for Medicare and Medicaid Services and the Behavioral Risk Factor Surveillance System, we examined trends in lower extremity amputation rates, diagnostic and therapeutic vascular procedures, and the use of preventive measures aimed at limiting the use of amputation procedures in the United States between 1996 and 2011.

Methods

We used Centers for Medicare and Medicaid Services claims to calculate rates of lower limb amputation between 1996 and 2011. Amputation procedures were categorized as above-knee, below-knee, and minor amputations. We included only the most proximal amputation per patient in any 1 year during the study period. Next, we calculated the number of revascularization procedures performed per 100 000 Medicare patients during the same time period, categorized as diagnostic lower extremity angiograms, endovascular lower extremity diagnostic and therapeutic interventions (such as angioplasty, stenting, or atherectomy), and lower extremity bypass surgery. Finally, we used data from the Behavioral Risk Factor Surveillance System (from 1996 to 1999) and Medicare beneficiary surveys (from 2000 to 2011) to examine secular trends in the prevalence of smoking and self-reported diabetes mellitus among patients older than 65 years of age, as well as rates of weekly glucose testing and annual foot examinations from a physician for diabetic patients. Frequency proportions were calculated by year, and significant changes were identified using nonparametric tests of trend. For our study, exemption from institutional board approval was granted.

The lower limb amputation rate has decreased by 45% over the last 15 years among Medicare patients, and the largest improvements have occurred in above- or below-knee amputations. During this same time period, significant increases have also occurred in the use of vascular procedures (both diagnostic and therapeutic) and preventive care.

Our observational findings cannot imply causation, and we recognize that our study presents no direct causative experimental evidence to explain the decrease in amputation risk. However, it is evident that the increasing use of vascular and preventive care, especially among patients with diabetes, has been temporally associated with lower rates of major amputation.3 While many debate whether open surgery, endovascular interventions, or hybrid strategies are most effective in limiting amputation,4,5 the importance of preventive measures has likely been underestimated. Future work examining relationships between preventive measures, revascularization, and amputation is necessary to help clinicians better define optimal strategies for limiting amputation.

Critical revision of the manuscript for important intellectual content: Goodney, Faerber, Schanzer, Zwolak.

Statistical analysis: Goodney, Faerber.

Obtained funding: Goodney.

Administrative, technical, or material support: All authors.

Study supervision: Goodney, Zwolak.

Conflict of Interest Disclosures: None reported.

Funding/Support: Dr Goodney was supported by a Career Development Award (K08HL05676-01) from the National Heart, Lung, and Blood Institute and a supplemental award from the Society for Vascular Surgery Foundation.

Role of the Funder/Sponsor: The funders had no role in the design and conduct of the study; collection, management, analysis, or interpretation of the data; and preparation, review, or approval of the manuscript.